I do understand, but think about the UK, it's what 80%+ White British? no escort is going to avoid their biggest market, unless they are in an area such as say Lewisham were they could afford to see only Black guys.
The thing is it's not like serving someone say a sandwich in Greggs is it? No Blacks would be racist if that was the case. What people forget is feelings, emotion and attraction is involved for both parties. We get the fat, old white men argument, I understand, but some women might prefer a fat old white man to say a Black bodybuilder it's not racist it's aesthetics, I prefer a size 16 White girl to say a size 8 Black girl that has a supermodel look - nothing to do with race. It is possible that some escorts do pick men based on their looks and can afford to; I knows there was one profile a while back where the escort only saw body builder types, dick must be this big etc. To assume attraction is irrelevant isn't the case, it might be rare, but let's not rule it out.